title: Hydranencephaly associated with interruption of bilateral internal carotid arteries.
abstract: Hydranencephaly is a rare and fatal central nervous system disorder where all or nearly all of the bilateral cerebral hemispheres are absent. The extensive hollow cerebrum is replaced with cerebrospinal fluid. Clinically, the differential diagnoses of hydranencephaly include severe hydrocephalus and alobar holoprosencephaly. Nearly all cases are sporadic, involving approximately 1 in 5000 continuing pregnancies. The exact main cause is still unknown, but hydranencephaly is usually found to develop secondarily to the occlusion of cerebral arteries above the supraclinoid level. We present the case of a 1-month-old male infant with hydranencephaly initially thought to be severely hydrocephalus via routine antenatal intrauterine sonography performed at 35 weeks of gestation. Hydranencephaly was confirmed by brain sonography, brain magnetic resonance imaging and magnetic resonance angiography postnatally. We discuss several imaging features that are helpful in distinguishing hydranencephaly from extreme hydrocephaly. Different theories that have been recently proposed regarding the origin of hydranencephaly are reviewed.
authors.affiliation: Division of Genetics, Department of Pediatrics, Chung Shan Medical University Hospital, Taichung, Taiwan.
authors.forename: Yeak-Wun
authors.initials: YW
authors.lastname: Quek
authors.forename: Pen-Hua
authors.initials: PH
authors.lastname: Su
authors.forename: Teng-Fu
authors.initials: TF
authors.lastname: Tsao
authors.forename: Jia-Yuh
authors.initials: JY
authors.lastname: Chen
authors.forename: Yan-Yan
authors.initials: YY
authors.lastname: Ng
authors.forename: Jui-Ming
authors.initials: JM
authors.lastname: Hu
authors.forename: Suh-Jen
authors.initials: SJ
authors.lastname: Chen
mesh_terms: D000328:Adult; D002343:Carotid Artery, Internal / Q000002:abnormalities*; D005260:Female; D006801:Humans; D006832:Hydranencephaly / Q000175:diagnosis* / Q000000981:diagnostic imaging; D007231:Infant, Newborn; D018810:Magnetic Resonance Angiography; D008279:Magnetic Resonance Imaging; D008297:Male; D011247:Pregnancy; D016216:Ultrasonography, Prenatal